Design for a backplate for a bathroom fixture



FIG. 1 is a perspective view of a backplate for a bathroom fixture which embodies my design;

FIG. 2 is a front-elevational view thereof;

FIG. 3 is a rear-elevational view thereof;

FIG. 4 is a left side-elevational view thereof, the right side-elevational view being a mirror image thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof. 

The ornamental design for a backplate for a bathroom fixture, as shown and described. 